This invention is an improvement over the structures of U.S. Pat. Nos. 2,983,216 and 4,059,045 which are incorporated herein by reference.
The invention relates to protective caps or rain covers for the open ends of upright exhaust pipes of internal combustion engines. Such covers are mounted for rocking movement on exhaust stacks to prevent entry of rain, insects, dust and the like when the engines are not operating. More particuarly, the invention relates to means for preventing, or at least reducing, the loud noises associated with the opening and closing of the covers.
Among the known prior art directed to attempting to reduce the noise of rain covers is a "Weather Cap Construction" disclosed in U.S. Pat. No. 3,523,499. The present invention distinguishes over this patent by virtue of a novel combination with a rain cover of improved stop means and bumpers as set forth hereinafter in the body of the specification.
The structure of the prior art U.S. Pat. No. 3,523,499 is complex and expensive in that in order to make the combination of the fulcrum arm and the clamping structure out of an integral member of sheet metal it is necessary to utilize sheet metal that has a relatively wide dimension. The fulcrum arm and clamp structure must either be stamped from blanks which are individually cut or, if stamped in a progressive die on a continuous basis must be made from strip material that is wider than the width of either the clamp portion or the leg portion. In either case the device is expensive to manufacture.
The invention herein utilizes a structure in which the clamp portion and the pivot support are formed of strip material whereby not only is there practically no scrap during fabrication, but the forming and shaping can be effected in bending, punching, welding and the like fixtures rather than in expensive dies as required for the said U.S. Pat. No. 3,523,499.
Still another problem with prior art devices like those of the said U.S. Pat. No. 3,523,499 is that they occupy large space. The vertical profile of the exhaust stack of a vehicle upon which they are installed is increased and they require larger containers for shipment and storage. The invention on the other hand, by virtue of its novel structure, provides a very low profile. This is achieved by making the clamp and arm support out of strap material, having the pivot and clamping fastener in horizontal alignment and by a major portion of the counterweight vane below the clamping means rather than above it.
A further problem which is solved by the invention is the wearing out of plastic bumper means. According to the invention, the bumper means are readily removable and replaceable in one case and prevented from extrusion flow in another case.